1. Field of the Invention
A method and apparatus for purifying potable water in a highly compact concentric disk device for domestic use and other applications.
2. Description of the Prior Art
The presence of lead and chlorine in drinking water is objectionable for human consumption. It, therefore, is considered desirable and often necessary, to subject drinking water containing such chemical substances to treatment prior to its use.
Perhaps the most common and least tolerable chemical impurities in drinking water are lead and chlorine. Lead poisoning (plumbism) is a chronic disorder, sometimes punctuated by recurrent acute symptomatic episodes, that may result in chronic irreversible effects (e.g., cognitive deficits in the child and progressive renal disease in adults). Chlorine usually cause mild pain and inflammation or oral and Gl mucosa; cough, dyspnea, vomiting, skin vesicles and also adversely affects the taste of the drinking water and canned foods.
One of the standard methods of treating drinking water is by reverse-osmosis. In the treatment of water by this process pure water molecules are filtered through a special plastic membrane under pressure, leaving the chemical impurities behind.
This method while reasonably effective, has always possessed certain disadvantages, such as low flow rate of purified water, i.e. typically 3 hours per gallon. Furthermore, this system is expensive to buy ($400.00 to $750.00), and may require professional installation, and waster water at a rate of about 15 to 30 gallons a day.
A well known and effective method for removing lead is the distillation process, using distillers. A distiller uses electricity to boil water. The rising steam leaves lead behind, because lead's boiling point is far higher than water's. A fan helps condense the steam onto metal coils, an clean water drips out the spout into a collection jug. One of the disadvantages of this method is its very low rate of purified water production, i.e. seven hours per gallon. Although a distiller's initial price ($100.00) is less than that of a reverse-osmosis system, it costs much more to operate. Distilling 1,000 gallons will have an average cost of $237.00 at the nation's average electricity rate of 8.25 cents per kilowatt-hour.
Another device for water purification is the so-called undersink filters. These devices are attached to the cold-water line and typically send water through a prefilter, then through a lead-removing filter and out the unit's countertop spigot.
This device is suitable for a household that uses lots of water. They are less expensive and easier to install than reverse-osmosis devices, however, their lead removal effectiveness is less, typically 88-92%. Price ranges from $189.00 to $330.00 with an operating cost from $44.00 to $226.00 per year.
Another method of purifying water at home is by using countertop filters. A diverter with a valve inside attaches to the existing faucet, in place of the aerator. When the filter is not in use, water flows from the faucet as usual. To draw treated water, a diverter valve is actuated which shunts water through the filter and out through the unit's spigot.
Like an undersink filter, a countertop model provides filtered water on demand, but it requires no major changes in plumbing. It does take up counter space, and its connector tubes can get in the way when you're using the sink. Prices range from $65.00 to $227.00 with an annual operating cost of $25.00 to $110.00.